The target for curative arrhythmia ablation is typically near the site of earliest cardiac electrical activation during arrhythmia. However, current methods for localizing the earliest site of activation for atrial and ventricular tachycardia are inefficient, which contributes to ablation success rates of 70% or less for many of these arrhythmias.
Typically, the localization process involves point-by-point surveying of the surface of the heart using an intra-cardiac electrode catheter to search for the site of arrhythmia origin, which can be time consuming. This process is often performed by pacing at a number of points in the heart during normal rhythm until the paced cardiac activation pattern, determined by inspection of the surface and intra-cardiac electrocardiograms, “exactly” matches the cardiac activation pattern that was recorded during arrhythmia. This process is termed “pace mapping”. Though getting a closely matched pace map is often not difficult, achieving an “exact” match is commonly challenging and could benefit from specific information regarding where to move the catheter to improve the pace map match.
An alternate method of mapping is to capture the global cardiac activation pattern during arrhythmia in a single heartbeat using a multi-electrode, intra-cardiac array. This method is termed “non-contact mapping”. Though in concept the earliest site of arrhythmia activation can be readily located by this captured activation pattern, in practice this activation pattern may not have an exact correspondence to physical surface locations in the heart. This is particularly an issue in irregular chambers such as the left ventricle or dilated heart chambers, in which cases non-contact mapping may not be spatially accurate enough for targeting ablation and additional point-by-point contact mapping is required.
It would therefore be advantageous to provide a method that takes advantage of the accuracy of point-by-point mapping and speed of “non-contact mapping” to potentially improve the speed and accuracy of targeting ablation of arrhythmias such as atrial and ventricular tachycardia.